方法;PROCESS

摘要

本文揭示一种自生物琥珀酸原料产生琥珀酸二烷基酯之方法，其包含以下步骤：(a)将固体生物琥珀酸进料至第一反应器，在其中其与烷醇接触，该第一反应器系于使得能够发生自动催化酯化之适宜温度及压力下操作；(b)将自该第一反应器移除之包含未反应之琥珀酸、单烷基酯、二烷基酯、烷醇、水及杂质之流传送至位于反应区塔之顶部处或其附近之点，该反应区塔系于使得能够酯化该琥珀酸及进一步酯化该单烷基酯之温度及压力下操作，及将该流在逆流反应中传送至向上流动之额外烷醇；(c)自该反应区塔之底部处或其附近移除包含选自残余琥珀酸、单烷基酯、二烷基酯、杂质及烷醇之组份之流及将该流传送至底部流分离区，在其中分离该二烷基酯与烷醇、及该琥珀酸、单烷基酯及杂质；(d)使该琥珀酸及单烷基酯再循环至该反应区塔；(e)作为吹扫移除至少一些该等杂质；及(f)自该反应区塔之顶部处或其附近移除包含烷醇、水及有机组份之流及将该流传送至顶部流蒸馏区，在其中分离该烷醇与水及该等有机组份，及使该等有机组份再循环至该反应区塔。; (b) passing a stream removed from the first reactor comprising unreacted succinic acid, mono alkyl ester, dialkyl ester, alkanol, water and impurities to a point at or near the top of a reaction zone columm operated at temperatures and pressures to enable esterification of the succinic acid and further esterification of the mono alkyl ester, and passing said stream in counter-current reaction to upflowing additional alkanol; (c) removing a stream from at or near the bottom of the reaction zone column comprising components selected from residual succinic acid, mono alkyl ester, dialkyl ester, impurities and alkanol and passing said stream to a bottoms stream separation zone where said di-alkyl ester is separated from alkanol, and from the succinic acid, mono alkyl ester and impurities; (d) recycling the succinic acid and mono alkyl ester to the reaction zone column; (e) removing at least some of the impurities as a purge; and (f) removing a stream comprising alkanol, water and organic components from at or near the top of the reaction zone column and passing said stream to a top stream distillation zone where the alkanol is separated, from the water and from the organic components and recycling the organic components to the reaction zone column.